Method and means for marking radiographs



Aug. 15, 1933. H. s. SAWFORD METHOD AND MEANS FOR MARKING RADIOGRAPHSFiled Dec. 8, 1930 2 Sheets-Sheet 1 IN VEN TOR l/aro/d 8. San fora BYQwaaa M A TTORNEYS Aug. 15, 1933.

H. S. SAWFORD METHOD AND MEANS FOR MARKING RADIOGRAPHS Filed Dec;. 8,1950 2 Sheets-Sheet 2 DATE No COMPANY M NAME Harv/d 8 Saw/fora.

A ITORNEYS Patented Augil5, 1933 METHQD AND MEANS FOR MARKINGRADIOGRAPHS Harold S. Sawford, Ozone Park, N. Y.

Application December 8, 1930. Serial No. 500,826

9 Claims.

This invention relates to a method and means of marking radiographs, andhas for an object to provide complete identifying data directly on asmall marginal portion of the radiograph plate or film. (The terms plateand film are used synonymously herein.)

It has been a practice in the past to employ a metallic stencil markerplaced outside the cassette for making a mark directly on the plate, themetallic stencil being to a certain extent opaque to Roentgen rays. Thispractice has never proved very satisfactory for several reasons; Themarking stencil on account of its large size was apt tobe partly coveredby the object or part radiographed, so that the identifying marks wereeither too dark or too light or both, and were difficult to decipher.Furthermore, the amount of radiation employed varies greatly in makingradiographs of different parts of the body, very light exposures beingused for parts such as fingers, and very heavy-exposures for spines,etc. Since the opaqueness of the metallic stencil to Roentgen rays wasrelied on entirely for controlling the application of the I mark to theplate, and since the penetration of the rays through the metallic partof the'stencil varied greatly with. the lightness or heaviness of theexposure, the kind of mark secured was very uncertain. The stencil wasnecessarily located at the outer side of the first intensifying screen,which screen produced actinic raysin all areas exposed to any Roentgenrays and subjected the plate to the full effect of such actinic rays.The distance ofthe stencil from the plate also, mitigated against clearmarking because of second.- ary radiation. 7 a The informationwhichcould be, secured by the useof such a stencil was very meager,consisting generally of nothing more than an identifying series ofletters or number, so that the plate could only be actually identifiedthrough recourse to an index. As a consequence, it has been the morecommon practice to merely paste a paper label on r the plate, after thesame has been developed. This practice, however, involves the necessityof carefully indexing the plates before they are developed, sothatthecorrect label may be applied to each film Ithas the further drawbackthat the labels are apt to become detached or to be torn or obliteratedwhen the plates are handled. r

To the end that a compact,. complete and clear identifying legend may heapplied at the exposure of the plate,'I have contrived a means forinterposing a screen opaque to actinic rays between the plate and theintensifying screen at one side of the plate in the area to be marked,and a label generally transparent to actinic rays between the plate andthe intensifying screen at the opposite side of the plate in the samearea,

with the desired information marked on the label in the ink opaque toac'tinic rays. By this mans the actinic rays produced by the action ofthe Roentgen rays on the'first intensify- 5 ing screen in the markingarea may be prevent ed by the screen from reaching the film in thatarea, while the Roentgen rays which pass on through have relativelylittle elfect upon the film leaving it photographically active. Whenthese penetrating Roentgen rays reach the second intensifying, screen,the actinic rays produced come back through the label except in themarked areas. As a result of this arrangement, only the areas of theplate in registration with unmarked areas ofthe label'are exposed at allto the action of actinic rays, and since the label may lie directly incontact with the plate the marking is very clear. The label is 7preferably made of paper highly transparent to actinic rays, so thatclear results are obtained even with light exposure.

Alternatively the label may be positioned at the side of thefilm towardthe source of Roentgen rays, and the screen opaque to actinic rays maybe located at the opposite side of the film. The label then prevents thepassage through to the film of any actinic rays in the symbol areas,while the screen prevents the reflection back of any actinic rays fromthe lower intensifying screen onto any portion of the marking area.

In a preferred form of the'invention the label and the mark protectingscreen are made unitary, consisting of a single sheet of paper havingone half of its area printed in solid black and the other half leftwhite, with the exception of certain printed legends, and this sheet isadapted to be folded about its center to embrace a margin of the plate.

Other objects and advantages will hereinafter appear.

In the drawings forming part of this specification:

Figure l is a sectional elev'ationof acassette having a plate and amarker secured therein; Figure 2 is a perspective view of the markeremployed in Figure 1;

Figure 3 is a back view of unfolded;

Figure 4 is a face view of the unfolded marker the marker shown showingthe" screen area thereof printed in black;

Figure is an elevational view, partly broken away, of a film or platehaving the marker applied thereto;

Figure 6 is a fragmentary, edge view on a larger scale than the otherfigures, showing the marker applied to the film or plate; and

Figure '7 is a plan view of an intensifying screen employed inaccordance with one method of practicing the invention.

The cassette comprises a ring frame 1, a cover 2 preferably of sheetaluminum or other suitable strong material transparent to Roentgen rays,a sheet of black paper 3 opaque to actinic rays, and a fluorescentintensifying screen 4 applied to the under side of the sheet 3. A plate5 having coatings 6 and 7 of a photographical- 1y active emulsionapplied to the opposite faces thereof is placed against the screen 4with a foldable marker 8 embracing a margin thereof. The cassette alsoincludes a retaining plate 9 which carries a felt backing 10. A secondintensifying screen 11 of fluorescent material is carried by the feltbacking 10. The retaining plate 9 is held to the ring frame 1 to securethe photographic plate and the marker in place by means of a clampinglatch 12 pivoted on the back of the retaining plate. The source ofRoentgen rays is located above the cassette as the same is illustratedin Figure 1. The marker 8 consists of a sheet of paper having an easyfold line 13 along the longitudinal center thereof provided, forexample, by a line of perforations. The upper half of the marker isprinted in solid black to make a screen 14 thereof opaque to actinicrays, and the lower half is printed with a suitable legend 15 toindicate the information required to be filled in. Such information isillustratively indicated in script. Both the printed legend and thematter written in script are formed of an ink opaque to actinic rays, orthe script portion may be written in pencil.

. fying screen 4 and the plate 5, and the label area being disposedbetween the lower intensi fying screen 11 and the plate 5. When theparts have been assembled in the relation shown in Figure l, the plateis ready for an exposure. When the exposure is made, the Roentgen rayspass readily through the aluminum plate 2. Any actinic rays which may bepresent are absorbedby the sheet 3. The Roentgen rays falling upon thefluorescent intensifying screen 4 produce actinic rays which have thecharacteristic of being much more effective upon the photographicallyactive substance on the plate 5 than the unconverted Roentgen rays. Thescreen portion 14 of the marker 8 prevents the passage through to theplate of the actinic rays from the screen 4, permitting only theRoentgen rays to pass. The Roentgen rays pass through both folds of themarker to the lower fluorescent intensifying screen, and there result inthe further production of actinic rays. The actinic rays thus produced,or a considerable proportion of them, pass back through the label andreach the plate in all areas thereof not in registration with theprinted or written matter on the label. The printed and written areas ofthe label are again protected from the action of the actinic rays, andsince the photographic plate lies directly in contact with the label,the marking on the label is caused to be clearly and distinctly shown onthe plate when the plate is subsequently developed.

As has already been mentioned, the marker might be disposed in theopposite way from that described, with the label portion interposed between the photographic plate and the upper intensifying screen and withthe screen portion interposed between the photographic plate and thelower intensifying screen. In this case the screen portion would act toprevent the reflection back of any actinic rays from the lower screen,and would thus prevent the marking from being rendered indistinct byreflected rays.

In Figure 7 disclosure is made of a modified means of practicing theinvention, the arrangement in'this case consisting in the printing onone of the intensifying screens, say the screen 4, of an area 16 ofsolid black. This black area is designed to be used as a protectivescreen in lieu of the screen area of the marker'S. The printing may beapplied to either one, but not to both, of the intensifying screens. Insuch case the label will always be placed between the photographic plateand the unprinted intensifying screen. I prefer, however, to follow thepractice illustrated in Figures 1 to 6, inclusive, since the foldedlabel may be conveniently and accurately placed with reference to theplate and constitutes a fool-proof means for assuring that the markerscreen will be located at the opposite side of the plate from the label,and that it will be in exact registration with the label.

The markers may be of various colors and shades of colors according tothe degree of transparency to actinic light which is desired, certainreds, yellow, and certain shades of green being useful in thisconnection.

The term completely opaque as used in the appended claims is notintended to refer to the degree of opaqueness of the shielding means butrather to the uniformity or solidity of the shielding in the markingarea.

I have described what I believe to be the best embodiments of myinvention. I do not wish, however, to be confined to the embodimentsshown, but what I desire to cover by Letters Patent is set forth in theappended claims.

Iclaim:

1. The method of marking radiographs, which comprises interposing aphotographic plate between a pair of fluorescent intesifying screens,

interposing between the plate and one of the intensifying screens, ascreen completely opaque to actinic rays through the entire markingarea, interposing symbols opaque to actinic rays between. the plate andthe other intensifying screen within the marking area, and taking theexposure.

2. The method of marking radiographs, which comprises interposing aphotographic plate between a pair of fluorescent intensifying screens,

shielding a marking area completely from actinic rays emanating from oneof the intensifying screens, shielding symbol areas within the markingarea fromactinic rays emanating from the other intensifying screen, andtaking the exposure.

3. In combination, a photographic plate, fluorescent screens at oppositesides of the plate, and a sheet of material folded about a marginalportion of the plate, and having the folds there- 1 of interposedbetween the plate and the respective intensifying screens, one of saidfolds being completely opaque to actinic rays, and the other beinggenerally transparent to actinic rays, but opaque to such rays in symbolareas.

4. A radiograph marker comprising a piece of sheet material having alongitudinally extending fold line provided substantially along themiddle thereof, and having one of its folds completely opaque to actinicrays, and the other transparent to actinic rays except in selectedareas.

5. A radiograph marker comprising a screen completely opaque to actinicrays, and a label ggenerally transparent to actinic rays, the screen andlabel being hingedly connected to'one another and adapted to be foldedagainst opposite faces of a photographic plate.

6. A radiographic marker consisting of a sheet of material, one half ofsaid marker being uniformly treated to prevent or minimize marking of aphotographic plate from the side of the plate at which it lies, and theother half being generally transparent to actinic rays and adapted 7. Afluorescent screen for use in radiographing, said screen having alimited portion of the exit face thereof rendered uniformly opaque toactinic rays and adapted to overlie amarking area of the photographicplate.

8. A cassette for use in radiographing, including a pair of fluorescentscreens adapted to have a photographic plate placed between them, one ofsaid screens having an area of its surface that faces toward the platerendered uniformly opaque to actinic rays.

9. The method of marking radiographs, which comprises marking symbolsopaque to actinic rays upon-a label generally transparent to actinicrays, interposing the label between a photographic plate and afluorescent screen at one side of the plate, completely shielding themarking area of the photographic plate against exposure to actinic raysfrom the side opposite that at which the label is placed, and taking theexposure.

HAROLD S. SAWFORD.

